Electrical connector assemblies of the locking type are well known in the connector industry. Normally, the female portion of such a connector assembly has two or more arcuate, circularly arranged slots, while the male portion has an equal number of arcuate blades which are dimensioned and arranged for insertion into the slots of the female portion by a simple axial movement, and then, via a rotation of one or both of the connector portions the blades can be moved into a position from which they can not be separated by simple axial movement. To accomplish this, one or more of the blades usually has an L-shaped configuration in which the laterally extended portion, or flag, of the blade engages a recess or shelf within the slot of the female portion as a result of the rotation.
The male and female portions typically have a retainer body with either blade contacts or female contacts and a cover releasably coupled onto the retainer body by either two or more screws, or threads formed on the cover and retainer body (screw-on), or a bayonet connection. This screw-on or bayonet connection between the retainer body and the cover presents a unique problem when the male and female portions of the electrical connector assembly are coupled together. In particular, the unlocking motion required to unlock a locking type electrical connector assembly requires a counterclockwise rotation of the cover in the same counterclockwise direction used for coupling the threaded or bayonet-mounted cover from the retainer body. Accordingly, the cover of many prior art electrical connectors occasionally will uncouple from the retainer body during the unlocking rotation of the electrical connector assembly.
The most common way to overcome inadvertent loosening or uncoupling is to provide the cover and the retainer body body with a separate locking latch. However, a separate locking latch increases the manufacturing costs and requires a secondary unlocking action by the user. Another way to overcome inadvertent loosening or uncoupling is to select a thread pitch between the cover and retainer body such that the unscrewing torque for uncoupling the cover from the retainer body is substantially above the blade unlocking torque for uncoupling the male portion from the female portion However this introduces other problems such as the tightening torque exerted by an individual can cause the threads between the cover and the retainer body to self lock. In other words, the cover becomes very difficult to unscrew from the retainer body. Accordingly, the threads between the cover and retainer body typically have a very shallow pitch so that the cover can be removed from the retainer body with very little force.
Examples of various locking connectors are disclosed in the following U.S. Pat. Nos. 2,396,901 to Tiffany; 3,393,395 to Hubbell; 3,784,961 to Gartland; 3,945,702 to Poliak et al; 4,213,667 to Wittes; and 5,046,961 to Hoffman.
In view of the above, it is apparent that there exists a need for a lockable cover for an electrical connector of the locking type which will prevent inadvertent uncoupling of the cover from the retainer body. This addresses this need in the art, along with other needs which will become apparent to those skilled in the art once given this disclosure.